Originally Posted by
KerryIrons
Get out a ruler and measure the length of 24 pins (12 inches of original length). If it measures over 1/16" (1.6 mm) elongation, replace it. Chain checkers are notorious for their inaccuracies. Rulers are NEVER wrong.
the ruler he or she uses will be metric, i'd guess... a swiss or germanic last name... "Google Translate" mentioned, etc.
12.7mm bicycle chain link pitch, 609.6mm in two feet, ... about 3mm in 609.6mm length equals .5% wear...
two feet, 610mm, on a chain, is an easier read on a ruler
i check chains by a push-pull of three links.... and side motion too.
there is a technique using the chain, and pulling it outward from the chainring too... that can also show chain ring wear, and the amount of pull out can vary by tooth count on the ring involved...so can be a bit misleading to most people.
the chain wear indicator stick takes away the doubt... totally perfectly accurate or not.
considering the recent Prices of a new "12 speed" ANYTHING... get the new chain now.